Membrane separators are key components in batteries and fuel cells. Currently, Nafion®, a perfluorinated polymer, is the current state of the art. However, Nafion® is costly. Non-fluorinated, hydrocarbons are more cost-efficient, yet exhibit poor oxidative stability, which in turn negatively impacts its durability. Thus, additional compositions are needed to provide improved polymers having enhanced oxidative stability without sacrificing performance. In particular, such improvements should allow the user to control or tune the amount or extent of the fluorinated or hydrophobic components of the polymer.